My fiancé and cousin are laying vinyl hardwood planks in my foyer. The entry part near the door is slab and carpet has been removed from the other part. They had to lay 1/4" wafer board to even that part of the floor with the slab. They started to lay the planks (which do have adhesive tabs around the edge) against the wall edge of the slab and wafer board, but the planks are not adhering to the floor. Should they prep the slab and board with a primer and/or sealer and adhesive before they lay the planks?

On a slab there needed to be a vaper barrier before anything went down. I never would have used wafter board on a floor like that, The moisture will make it fall apart.
I would have also used Allour flooring, it's a floating vinyl strip flooring and would have needed no glue at all.
What type do you have? Has anyone taken the time to read the directions on the box to see what's called for.
Also there's no such thing as vinyl hardwood planks, there either hardwwod or vinyl. They may just look like hardwood.

[QUOTE="misszee"]@ joecaption: The product is allure. After they thought the allure didn't adhere, they removed it. Since there is nothing on the slab or the wood, the wood can be removed. What would you suggest using to level that part of the floor with the slab? My fiancé said he read it and it said to put some type of base or primer on before laying the allure.

I've laid a few hundred boxes of Allour and never used any adhesive, It's a floating floor system.
I would first lay down 15 LB roofing felt over any bare slab taping the seams with packing tape. Then use a layer of 1/4 sanded plywood that gets Tap Coned to the floor using 5/16 flat head screws. (Tap Cons are special screws for concrete)
The Allour has a strip of adhesive under a strip of paper that gets peeled off and each piece is strick to the next one, not directly to the floor. That type flooring expands and contracts some so a gap must be left between the walls and the flooring or it will buckle.Allure Flooring Instructions | eHow.com

I've laid a few hundred boxes of Allour and never used any adhesive, It's a floating floor system.
I would first lay down 15 LB roofing felt over any bare slab taping the seams with packing tape. Then use a layer of 1/4 sanded plywood that gets Tap Coned to the floor using 5/16 flat head screws. (Tap Cons are special screws for concrete)
The Allour has a strip of adhesive under a strip of paper that gets peeled off and each piece is strick to the next one, not directly to the floor. That type flooring expands and contracts some so a gap must be left between the walls and the flooring or it will buckle.Allure Flooring Instructions | eHow.com

http://www.homedepot.com/catalog/pdf...f17da70f63.pdf
There talking about a clear sealer or even a product called Dri-Loc. Not a primer or paint. It has nothing to do with getting it to stick to the floor, it's to stop rising moisture and chemicals in the slab from getting to the flooring.